According to the thermodynamics analysis of spontaneous mineral of iron , we assumed : when sewage disposal , if sulphur is eliminated prior , this makes the consistency of iron ' s ion keep high relatively , it will react with phosphorus , produce heterosite , vivianite precipitate . this will decrease the interior load of the phosphorus in sediment , and reduce the consistency of the phosphorus in the dianchi lake 根据铁的自生矿物的热力学分析，提出设想：如果在污水处理时，优先脱硫，就使铁离子的浓度保持较高，与磷生成磷铁矿、蓝铁矿沉淀，就可以减轻沉积物中磷的内源负荷，进而降低滇池湖水中的磷的浓度。
